Robur remained impassible, and continued: "There is no progress for
your aerostats, my citizen balloonists; progress is for flying
machines. The bird flies, and he is not a balloon, he is a piece of
mechanism!"

"Yes, he flies!" exclaimed the fiery Bat T. Fynn; "but he flies
against all the laws of mechanics."

"Indeed!" said Robur, shrugging his shoulders, and resuming, "Since
we have begun the study of the flight of large and small birds one
simple idea has prevailed--to imitate nature, which never makes
mistakes. Between the albatross, which gives hardly ten beats of the
wing per minute, between the pelican, which gives seventy --"

"Seventy-one," said the voice of a scoffer.

"And the bee, which gives one hundred and ninety-two per second --"

"One hundred and ninety-three!" said the facetious individual.

"And, the common house fly, which gives three hundred and thirty --"

"And a half!"

"And the mosquito, which gives millions --"

"No, milliards!"

But Robur, the interrupted, interrupted not his demonstration.
"Between these different rates --" he continued.

"There is a difference," said a voice.

"There is a possibility of finding a practical solution. When De Lucy
showed that the stag beetle, an insect weighing only two grammes,
could lift a weight of four hundred grammes, or two hundred times its
own weight, the problem of aviation was solved. Besides, it has been
shown that the wing surface decreases in proportion to the increase
of the size and weight of the animal. Hence we can look forward to
such contrivances --"

"Which would never fly!" said secretary Phil Evans.

"Which have flown, and which will fly," said Robur, without being in
the least disconcerted, "and which we can call streophores,
helicopters, orthopters--or, in imitation of the word 'nef,' which
comes from 'navis,' call them from 'avis,' 'efs,'--by means of which
man will become the master of space. The helix --"

"Ah, the helix!" replied Phil Evans. "But the bird has no helix; that
we know!"

"So," said Robur; "but Penaud has shown that in reality the bird
makes a helix, and its flight is helicopteral. And the motor of the
future is the screw --"

"From such a maladee Saint Helix keep us free!" sung out one of the
members, who had accidentally hit upon the air from Herold's "Zampa."

And they all took up the chorus: "From such a maladee Saint Helix
keep us free!" with such intonations and variations as would have
made the French composer groan in his grave.

As the last notes died away in a frightful discord Uncle Prudent took
advantage of the momentary calm to say, "Stranger, up to now, we let
you speak without interruption." It seemed that for the president of
the Weldon Institute shouts, yells, and catcalls were not
interruptions, but only an exchange of arguments.

"But I may remind you, all the same, that the theory of aviation is
condemned beforehand, and rejected by the majority of American and
foreign engineers. It is a system which was the cause of the death of
the Flying Saracen at Constantinople, of the monk Volador at Lisbon,
of De Leturn in 1852, of De Groof in 1864, besides the victims I
forget since the mythological Icarus --"

"A system," replied Robur, "no more to be condemned than that whose
martyrology contains the names of Pilâtre de Rozier at Calais, of
Blanchard at Paris, of Donaldson and Grimwood in Lake Michigan, of
Sivel and of Crocé-Spinelli, and others whom it takes good care, to
forget."

This was a counter-thrust with a vengeance.

"Besides," continued Robur, "With your balloons as good as you can
make them you will never obtain any speed worth mentioning. It would
take you ten years to go round the world--and a flying machine could
do it in a week!"

Here arose a new tempest of protests and denials which lasted for
three long minutes. And then Phil Evans look up the word.

"Mr. Aviator," he said "you who talk so much of the benefits of
aviation, have you ever aviated?"